Exp. 5 Flow Chart

Exp. 5 Flow Chart - It is best to wave the flame under the...

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CHE101 Lab Peter Zareba Experiment 5 Flow Chart October 7, 2007 Support a clean crucible and cover on a wire triangle and heat them for 5 minutes until thoroughly dry Let cool to room temperature Weight on analytical balance and record mass in Table 5.1 Use tongs to handle crucible Transfer 0.50g of unknown mixture of NaHCO3 and Na2CO3 Determine the mass of crucible, cover, and mixture and record in Table 5.1 Place crucible in wire triangle again and place the entire apparatus under the hood Carefully measure 3mL of concentrated (12M) HCl solution into a 10mL graduated cylinder Working under the hood, add the HCl solution one drop at a time to the NaHCO3 - Na2CO3 mixture in the crucible Wait for reaction t subside before adding the next drop of acid to avoid splattering and loss of material. After all is added, heat gently to drive off excess acid and water
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Unformatted text preview: It is best to wave the flame under the crucible and to keep the cover partially open The rate of heating much be gentle enough to prevent the acid from boiling and splattering the mixture When a dry solid appears, heat the crucible in the full flame of the Bunsen burner for 10 minutes Allow to cool for 15 minutes Weight the crucible, cover, and residue and record mass To ensure that all volatile substances have evaporated, reheat the crucible, cover, and residue for 5 minutes All to cool for 15 minutes and reweigh If the change of mass is more than .001g, repeat, cool and weigh. Use this constant mass to calculate the percent composition of the mixture. Duplicate run? Perform calculations...
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This note was uploaded on 04/18/2008 for the course CHE 101 taught by Professor Churchhill during the Fall '08 term at SUNY Buffalo.

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